Skip To The Main Content

Case Study: Vacuum Contactors Built For Mining Applications

History shows that arcing mediums have changed from oil to air and now to vacuum, a proven technology for 35 years. Vacuum contactors are now used in many applications around the world, and are especially significant in mining applications. Here, we will point out challenges that are faced in the mining industry, the advantages of the vacuum contactor and Joslyn Clark successes in mining applications.

Please accept marketing-cookies to watch this video.

Challenges in Mining Applications

The mining industry has some of the world’s harshest environments and most demanding applications. Throughout many years of developing technology, vacuum contactors have been finetuned for this “heavy duty” environment where reliability is critical and space is limited. Unfailing power switching and motor starting solutions are necessary to ensure dependable productivity in potentially hazardous surroundings. To answer the call for such a profound device, Joslyn Clark designed a differentiated contactor that features size, robustness and reliability. Joslyn Clark is widely respected by leading coal mine machine builders as one of the world’s leading manufacturers of contactor and starter switches. Our contactors were designed specifically for applications such as long wall mining equipment, continuous miners, conveyors, open pit mining, pumping, crushers, power centers and other related equipment. Joslyn Clark’s contactors ensure safe and dependable start up and operation of mining equipment. Spanning the medium voltage range from 600V through 1.5 kV (CV Series), <3.6 kV (VC Series), Joslyn Clark has the contactor and motor starter system solution to address all mining needs.

The engineering and manufacturing teams at Joslyn Clark understands that one of the main challenges in the mining industry is finding compact tools and devices because space is very limited. In general, vacuum contactors take up much less space than air break contactors. Joslyn Clark’s 1140V contactor was designed specifically for mining and the need for compact size which is a definite advantage in the tight confines of a mine. All of Joslyn Clark’s vacuum contactors are designed to be more rugged, compact, quiet and light weight than the conventional air break contactors.

Advantages of Vacuum Contactors for Mining

The vacuum contactor is considerably safer than air break in mining applications due to the containment of the arc and the contacts being sealed tight. When the arc is contained, the contactor is closed and shielded from elements in the environment that could spark a flame or even worse, an explosion. In an environment where dirt, dust, gas and other particles can fill the air, covering the arc greatly reduces these detrimental risks. Contacts are sealed air tight inside of a vacuumed bottle to protect the contactor from atmospheric contamination from particles like H2S chlorine, dust, salt and atmospheres. Also, Joslyn Clark vacuum contactors are fully phase insulated, offering greater safety benefits than traditional air break systems.

While safety is key, there are other features of the vacuum contactor that prove they are the best fit for the mining industry. For instance, these devices are known for their long mechanical and electrical life. They are built to withstand the elements and the test of time, with very low maintenance and little downtime required. Versatility is also an advantage of the vacuum contactor, as they may be mounted on any plane. This is ideal for small, tight packaging electrically held contactor circuits. All vacuum contactors come backed by Joslyn Clark’s reputation for durability and reliability.


Success Stories

Joslyn Clark has the experience and knowledge to design and manufacture top of the line vacuum contactors that allow mining applications to be more productive and safe. As the world leader in vacuum contactors, starters and controllers, we are dedicated to continuously raising the bar for industry standards of life safety and fire protection. Our vacuum contactors are recognized by the leading mine machine builders for applications on long-wall mining equipment, continuous miners, conveyors, power centers and other related equipment.

These vacuum contactors are used by companies worldwide in not just coal mines, but in mining operations for precious metals and other materials. Mining companies and mining equipment manufacturers around the world have discovered the benefits of using Joslyn Clark vacuum contactors. One large mining machinery OEM located in the Appalachian Mountains began installing Joslyn Clark vacuum contactors after their customers repeatedly inquired about them, especially noting their compact dimensions.

Another mining OEM, in one of the Rocky Mountain states, shifted to Joslyn Clark vacuum contactors after its customers mentioned the benefits of lower maintenance costs. As the manufacturer explained to its customers, Joslyn Clark’s vacuum contactors cost slightly more upfront, but quickly pay for themselves in the benefits (reduced maintenance, less machine downtime, not to mention the intangible benefits, such as greater safety).


To sum it all up, vacuum as a switching medium has specific characteristics such as low arc energy, short arcing time, small movements required for arc isolation and arc containment. Therefore, they have long electrical and mechanical life, extremely compact size and no arc chutes or blow out coils that makes them most ideal for applications in the mining field.

See all Joslyn Clark Vacumm Contactors and Starters here